Signs are used in many applications where the message or information is expected to change from time to time, so that the information to be displayed by the sign also must change. Changeable-message signs are particularly useful to display numeric information that is anticipated to vary from time to time. Signs utilized to display numeric information, such as currency exchange rates or rates of interest on financial instruments, are but two examples of changeable-message signs. Because numeric information of those kinds is expected to undergo frequent if irregular changes, signs used to display that numeric information to customers or others should permit easy and prompt changing of the displayed numeric information.
Various kinds of changeable-message signs are known in the art. For example, there are signs that support individual alpha or numeric characters applied from a font of type provided for that purpose. The desired message is composed by selecting individual characters from the font and placing those characters on the sign, typically on a sign panel or other member specially designed to retain those characters in a horizontal or other particular alignment. The message, whether numeric or alphabetic, thus is made up of the individual characters selected from the font. The need for a separate font of individual removable characters is, however, a disadvantage of such signs. The individual characters making up the font should be stored in separate individual compartments when not attached to the sign, so that specific characters are easily located when needed to compile a new message. The characters removed from a former message must, accordingly, be placed in their proper compartments, to prevent time-wasting confusion when those characters are later needed. Furthermore, the individual characters making up the font are likely to become lost over time or damaged through frequent handling as the characters are attached to and removed from the sign. Further yet, some skill may be necessary in placing individual characters on the sign panel with the exact proper alignment, to assure that the resulting message has an attractive and professional appearance providing a positive image of the organization sponsoring the message.
Another known kind of sign uses electronic displays to produce selectively variable numeric or alphabetic information. Those electronic displays usually operate by activating selected elements in a matrix of display elements. Each character of an available font is produced by activating only those matrix elements required to define that character, in a manner similar to the digital displays found on many calculators and timepieces. Such electronic display signs are best suited for displaying information that may change from minute to minute, such as financial information at a stock brokerage, but the relatively high cost of those signs makes them impractical for applications where the displayed information may change, at the most, one or two times each day.
Accordingly, it is an object of the present invention to provide an improved changeable message sign.
It is another object of the present invention to provide a changeable message sign that does not require a font of removable individual characters.
It is a further object of the present invention to provide a changeable message sign that is relatively inexpensive to manufacture.
It is yet another object of the present invention to provide a changeable message sign in which the message characters are easily changed to produce the desired characters.
Other objects and advantages of the present invention will become apparent from the following discussion.
Stated in somewhat general terms, the message sign of the present invention displays characters in a manner emulating a digital display, in that the characters are formed using character elements to define parts of a particular font of characters. However, unlike a digital character that uses electrical control to activate the selected character elements making up particular characters by covering the character elements not required for that character.
State with somewhat greater detail, the digital characters are formed on one or more sign panels carried by a sign body to display at least a portion of the panel. The sign panel carries at least one set of character elements that are mutually interrelated to define a predetermined group of indicia. Selected ones of those character elements may be covered in any one of several different patterns, so that only a subset of the character elements remains visible at the display location of the sign body. That subset of character elements corresponds to a certain character selected from the group of characters that the set of character elements can define.
Stated somewhat more particularly, the character elements on the sign panel function in a manner similar to the elements of a digital display. For example, in a preferred embodiment these digital elements form a standard "8" frame, meaning that the elements form that numeral when all elements remain uncovered. By covering selected individual elements of the digital display, other numerals in the set from 0 to 9 are formed, and those numerals become visible to an observer seeing the sign panel. The individual indicia elements making up the digital character may be of the same size, so that the cover members required to cover those indicia elements may likewise be of the same size to the greatest extent possible.
Stated in further detail, a message sign according to the present invention can have a sign panel made of steel or otherwise having a ferrous substrate. The individual cover members in that case are made of any suitable magnetic material so that the cover members are attracted to the ferrous sign panel. Each cover member thus is readily attachable to the sign panel to remain positioned over a selected character element of the character, yet is readily removable when necessary to change the character elements exposed to view. The sign panel and the cover members can be made sufficiently thin so that the sign insert can slidably fit into a channel within the sign body. Once the selected character elements are covered to define the desired arrangement of characters, the sign panel thus is inserted in the sign body and the resulting message becomes resistant to tampering. Moreover, each character of the resulting message has a uniform and attractive appearance that is difficult to obtain with signs whose messages are constructed from a font of removable characters. Because the cover members for the present sign function only to cover the indicia elements and do not themselves bear any visible information, most cover members can be relatively consistent in size and shape, making it easier to store and retrieve those cover members not in use to cover an indicia element.